package com.easybuy.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;

/**
 * 随机生成验证码
 *
 * @author SR·Y
 */
public class RandomNumUtil {

    public static final char[] CHARS = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
            '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M',
            'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
    /**
     * 图像
     */

    private ByteArrayInputStream image;

    /**
     * 验证码
     */
    private String str;

    /**
     * 构造函数
     */
    private RandomNumUtil() {
        init(); //初始化属性
    }

    /**
     * 获得RandomNumUtil实例
     */
    public static RandomNumUtil Instance() {
        return new RandomNumUtil();
    }

    /**
     * 获得图片验证图片
     */
    public ByteArrayInputStream getImage() {
        return image;
    }

    public void setImage(ByteArrayInputStream image) {
        this.image = image;
    }

    /**
     * 获得图片验证码
     *
     * @return
     */
    public String getStr() {
        return str;
    }

    public void setStr(String str) {
        this.str = str;
    }

    /**
     * 初始化
     */
    private void init() {
        //在内存中创建图像
        int width = 65, height = 20;
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        //获取图形上下文
        Graphics g = image.getGraphics();
        //生产随机类
        Random random = new Random();
        //设定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        //设定字体
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
        // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 155; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        // 取随机产生的认证码(6位数字)
        StringBuffer sRand = new StringBuffer();
        for (int i = 0; i < 4; i++) {
            String rand = String.valueOf(CHARS[random.nextInt(CHARS.length)]);
            sRand.append(rand);

            // 将认证码显示到图象中
            g.setColor(new Color(20 + random.nextInt(110), 20 + random
                    .nextInt(110), 20 + random.nextInt(110)));
            // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
            g.drawString(rand, 13 * i + 6, 16);
        }
        // 赋值验证码
        this.str = sRand.toString();

        // 图象生效
        g.dispose();
        ByteArrayInputStream input = null;
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        try {
            ImageOutputStream imageOut = ImageIO
                    .createImageOutputStream(output);
            ImageIO.write(image, "JPEG", imageOut);
            imageOut.close();
            input = new ByteArrayInputStream(output.toByteArray());
        } catch (Exception e) {
            System.out.println("验证码图片产生出现错误：" + e.toString());
        }

        this.image = input;/** 赋值图像 */
    }

    /**
     * 给定范围获得随机颜色
     */
    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255) {
			fc = 255;
		}
        if (bc > 255) {
			bc = 255;
		}
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

}
